Mobile phone and CCTV footage played a key role in the murder trial of Adebolajo and Adebowale. Clips showed the horrifying moment Fusilier Rigby was ploughed into by the men in a Vauxhall Tigra and the dramatic moment armed officers shot the killers.

But the most shocking clip to emerge from the scene showed Adebolajo in front of an eyewitness holding a camera.

Dressed in a black woolly hat, dark green, hooded jacket and dark-blue jeans, his hands are covered in blood. He wields a knife and a meat cleaver.

Agitated and restless, he then breaks out into a roaming and rambling rant, trying to justify his actions.

Addressing the camera, Adebolajo said: "The only reason we've killed this man today is because Muslims are dying daily by British soldiers.

"This British soldier is one - he is an eye for an eye and a tooth for a tooth.

Gruesome: Michael Adebolajo can be seen shortly after butchering Lee Rigby

"By Allah, we swear by the almighty Allah we will never stop fighting you until you leave us alone.

"So what if we want to live by the Sharia in Muslim lands? Why does that mean you must follow us and chase us and call us extremists and kill us?

"Rather, you lot are extreme. You are the ones. When you drop a bomb, do you think it picks one person or rather your bomb wipes out a whole family? This is the reality.

"By Allah, if I see your mother today with a buggy I would help her up the stairs, this is my nature.

"But we are forced through the Koran.... that we must fight them as they fight us. An eye for an eye and a tooth for a tooth.

"I apologise that women had to witness this today but in our lands our women have to see the same.

"You people will never be safe. Remove your Governments - they don't care about you.

"Do you think David Cameron is going to get caught in the street, when we start busting our guns, do you think your politicians are going to die. No, it's going to be the average guy, like you and your children.

"So get rid of them. Tell them to bring our troops back so you can all live in peace. Leave our lands and you will live in peace.

"That's all I have to say."

As he closes his frenetic speech, the murderer turns back towards Fusilier Rigby's dead body, where his associate Adebowale waits.

TV watchdog Ofcom launched an investigation over the decision by broadcasters to air some of the footage before the watershed.

Ofcom is investigating BBC News, 5 News, ITV News, Channel 4 News and Sky News among others, following a number of complaints about the footage obtained by the bystander on a mobile phone.

It is assessing whether the footage was appropriately scheduled for children and whether any potential offence could be justified by the context.